Pearl - OC-7 ( Octaver )

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.
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chromedoutgrillz
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Post by chromedoutgrillz »

I was just wondering this.
Would there be any real advantage to swapping the Fet at the input of this for an opamp (I just thought it would probably be easier to source the parts if I drew up a design in DIY layout creator for this)


http://files.muziq.be/schematics/pearl_oc-07.jpg

Ta

Sam

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Bernardduur
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Post by Bernardduur »

Hmmm, dunno, but I have an original of someone has questions on this pedal :D
'No more....... loud music.......'
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puppiesonacid
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Post by puppiesonacid »

Bernardduur wrote:Hmmm, dunno, but I have an original of someone has questions on this pedal :D
yeah, how usable is it? does it really do what its designed to do well? or is it kinda cheesey sounding? always though that having the dry signal and an octave above and below simultaneously would be interesting.


Thanks,


puppiesonacid

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Bernardduur
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Post by Bernardduur »

puppiesonacid wrote:
Bernardduur wrote:Hmmm, dunno, but I have an original of someone has questions on this pedal :D
yeah, how usable is it? does it really do what its designed to do well? or is it kinda cheesey sounding? always though that having the dry signal and an octave above and below simultaneously would be interesting.


Thanks,


puppiesonacid

To be quite honest, I never use it :) It sits in its original box doing nothing......... but the sound is kinda nice. The octaves down are great but not that really special (compared to a Boss for example). The octave up is more fuzz-ish and not that loud. There is a mod to make it a tad more louder and then it becomes more usuable......
'No more....... loud music.......'
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chromedoutgrillz
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Post by chromedoutgrillz »

there's a DIY build available already at :
http://gaussmarkov.net/wordpress/circui ... ver-clone/

But I wanted to make one that didn't use SMD components

Looking at the schem again, I'm pretty sure the FET at the input is being used as a buffer, so could probably be omitted, whether this has a noticable effect on the rest of the pedal is what I'm unsure of...
I'll keep posting as I get on with the Layout etc...
As for the loudness of the octave up, there's a trimmer pot in that section,I think tweaking that might give a louder output..

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kierc
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Post by kierc »

That's so strange.. Just the other day I was really thinking out some plans to build an octave up + down with a dry signal to mix up things and see how it would sound... really want to do it now!
The sound sample he posted sounds pretty nice, but if it handled chords a little it'd be even better!

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Post by Fuzzer »

The Octron made by Foxrox does that, you can check it out to get some ideas...
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Ronsonic
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Post by Ronsonic »

That input FET is indeed just a buffer. If you're going to wire it up with true bypass like a true pedal hacker you won't need it or the IC switch over on the right side of the schematic that it connects to.

Leave out R1, C1, 2, Q1 and R3 on that side and C13, R19 on the other end.
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chromedoutgrillz
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Post by chromedoutgrillz »

Thanks for the reply ronsonic...
I've already chopped the original bypass part of the circuit out, and got the majority of the circuit drawn up in DIY layout creator,with the fet in,I've scrapped the idea of adding an addtional opamp buffer,as it'll not fit into a BB sized box,I'll probably just add an extra hole on the board and check the differences in omitting that first fet (the opamp following this should hopefully suffice...
I''ve got a few ideas to trick this box out,like splicing in tone controls for the octaves too,as the schematic shows it should be easy enough to do (something along the lines of the 'rat' tone controls,or Mark hammers Stupidly Wonderful Tone Control),and messing with the 4017 idea from the Rocktave Octave to give harmony notes...
Thanks again

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